Features‎:‎‎- Portable wearing style design‎,‎ perfect for outdoor sports‎- High speed USB 2.0 jack for charging and file transfer‎- Supports external TF / micro SD card up to 8GB ‎(‎ not included ‎)‎‎- FM radio function‎,‎ it can receive signals from your local station‎- Powered by rechargeable lithium‎-polymer battery and continuously working for 4 hours‎- Charging time about 2 ‎- 3 hours‎- Frequency response‎:‎ 20 ‎- 20000Hz‎- SNR‎:‎ over 85dB Package weight‎:‎ 0.094 kg Product Size‎(‎L x W x H‎)‎‎:‎ 14.20 x 12.50 x 2.10 cm / 5.59 x 4.92 x 0.83 inches Package Size‎(‎L x W x H‎)‎‎:‎ 19.50 x 17.00 x 5.50 cm / 7.68 x 6.69 x 2.17 inches Package Contents‎:‎ 1 x Sport MP3‎,‎ 1 x USB cable